“Garlandite” is the name of an inhabitant of Garland, Texas. The name “Garlandite” has been cited in print since at least 1891.
 
   
Wikipedia: Gardland, Texas
Garland is a city in the U.S. state of Texas. It is a large city northeast of Dallas and is a major part of the Dallas-Fort Worth Metroplex. It is located almost entirely within Dallas County except for small portions in Collin County. As of the 2010 census, the city had a population of 226,876, making it the twelfth-most populous city in Texas and the 87th most populous city in the United States.
 
In 2008, CNN and Money Magazine released their list of the Top 100 Places to Live, and Garland was ranked number 67. The city’s comfortable, hometown feel in the midst of a thriving metropolitan area was just one of the outstanding characteristics mentioned in the report.
 
17 August 1891, Dallas (TX) Morning News, “Garland,” pg. 3:
The following Garlandites attended the White Rock camp meeting last Sunday: ...
 
16 June 1897, Dallas (TX) Morning News, “Round About Town,” pg. 8, col. 4:
County Commissioner E. H. Halsell remarked to Round About yesterday: “The annual picnic of the Garland people will take place on June 26, and there will be feasting and merry-making from morn till night. The good house wives are baking cakes already and there will be roast pig, barbecued beef and mutton, boiled ham and fried chicken that will make the mouth water. When we Garlandites invite our friends to a picnic we feed ‘em.”
   
10 October 1904, San Antonio (TX) Daily Express, pg. 4, col. 3:
Garlandite Touched at Dallas.
Dallas, Tex., Oct. 9.—(Special.) A man claiming to reside at Garland reported to thje police that he had been knocked in the head and robbed last night of $110.
 
4 April 1958, Denton (TX) Record-Chronicle, pg. 8, col. 2:
MRS. AMERICA CONTEST
Garlandite Wins;
Dentonite Places
 
D Magazine (Dallas, TX)   
Published 5.01.1992
NATIVE SON My Home Town
Searching for the “real” Dallas, a native son ponders time, memory, barbecue, the Cotton Bowl and a certain je ne sais quoi, y’all
Chris Tucker
(...)
Yes, I’ve spent all but four of my 41 years living within 15 miles of downtown Dallas; not always in the city proper but close enough so that it made no sense to establish a separate suburban identity as a Carrolltonian or a Garlandite.
 
Google Books
Garland:
A contemporary history
By Richard Abshire
San Antonio, TX: Historical Pub. Network
2009
Pg. 6:
As the twentieth century dawned, Garlandites could be forgiven for believing that bad days were behind them and the best was yet to come.